This invention relates to a system which controls travelling of trains which are provided with driving wheels driven by a motor. Trains of this type are controlled in such a manner that the trains are stopped selectively at each station or before a junction or a joint arranged in the middle of the travelling rail. For this travel control, each stopping position has a target plate which can be switched between inactive and active positions. Each train has a 10 proximity switch for sensing a target plate, which is kept in an active position. Conventional systems have previously been composed so that each train is stopped when a target plate is sensed by the proximity switch, and each train at halt is started by switching the target plate to retracted or inactive position and by turning off the proximity switch.
A system of conventional composition, as described above, requires an actuator to switch the target plate between active and inactive positions as well as two limit switches for making sure that the target plate is properly switched to active or inactive positions respectively; this is expensive because of the number of parts involved. Moreover, the system can lead to an accident, since a train, which should be stopped, may go past without stopping should the target plate fail to return to its active position due to the actuator going out of order.
In view of the foregoing, a primary object of this invention is to provide a system to control travelling of trains which requires no actuators to switch positions of the target plate, yet can stop a running train at the position of the target plate, start a train at a halt, or even to keep a train running without stopping in some cases. For travel control of trains of this type, a code plate is mounted on the travelling rail of the trains. A code reading means is provided at the side of the trains, and travelling of the train is controlled on the basis of the information obtained from the code reading means.
In a travel control system of the conventional type, the code plate has a timing indicator apart from two or more parallel indicators which comprise travel control codes. The travel control codes are read in accordance with the ON/OFF state of other detectors, when the detector which reads the timing indicator is turned to an ON position. With a travel control system of conventional type, as described above, the code plate requires a timing indicator, which makes the code plate wider. Moreover, the detector required for reading the timing indicator, makes the number of parts involved larger. Accordingly, such a travel control system is disadvantageous in view of the cost.
Another object of this invention, therefore, is to provide a travel control system which can read control information of the code plate and accurately control travel of the train without using any timing indicator or detector.
For a control system which uses code plates as described above, the code plate is attached to the guide rails. Heretofore, the code plate has been fixed with bolts onto screw holes drilled at fixed positions on the guide rails or by using brackets which are welded to such fixed positions. With this construction, it is necessary to determine in advance the exact positions for attaching the code plates on the guide rails, and to accurately drill the holes or to attach the brackets. Following such procedures, it is rather difficult to attach the code plate precisely despite the care taken in attaching the code plate. Moreover, it normally is not possible to actually run a train car for trial, while temporarily fixing the code plate, in order to adjust the attaching position of the code plate according to the test result, and to fix the code plate after adjustment.
A further object of this invention, therefore, is to make it easy to attach the code plate accurately onto the guide rails. For trains which use a driving trolley of monorail type guided by one guide rail, the reduction gear placed between the motor and driving wheel has heretofore been arranged in parallel to said guide rail, at one side of the driving wheel, and the motor has been attached to the free end of the reduction gear so that the rotary axis is located on one side, oriented longitudinal direction which is parallel to the guide rail. With a transporting train of such conventional type, the center of gravity of the driving trolley is substantially offset from the center line of the guide rail, to the side of the reduction gear and motor, and comparatively large turning forces in the transverse direction are applied to said driving trolley. Accordingly, the anti-vibration rollers, positioned on the side of the reduction gear and motor become greatly worn out, which has been a cause of one-sided wear of the driving wheel. In addition, a costly, right angle, crossing-type gear transmission means, such as a worm gear, bevel gear, or hypoid gear, must be used for the reduction gear because the axis of the motor crosses at right angles with that of the propulsion wheel.
Still another object of this invention, therefore, is to avoid large lateral turning forces being applied to the driving trolley while eliminating the need for costly transmission gears between the motor and the driving wheel.
Other objects and advantages of the present invention will be clear from some preferred embodiments of this invention described below.